This invention relates to a pen with illuminator allowing users to write even in the dark by illuminating the surface to be written on.
This illuminable pen provided with the illumination means is known from, for example, U.S. Pat. Nos. 4,737,894, and 4,890,204. These known pens, however, employ a lamp of resistance type which has, however, problems relating to heat-emitting, relatively large required space, weight, electric consumption, etc.
As a proposition to eliminate these disadvantages, a pen with an illuminator is disclosed by U.S. Pat. No. 5,131,775, in which an LED(light emitting diode) is employed as the illuminator. The LED includes a pair of chips embedded at both sides of a writing element to illuminate uniformly the writing surface. However, embedding of two chips in one LED causes several problems in productability, workability, increase of cost, ete. It needs, moreover, registor to cause the cost to increase correspondingly.
Accordingly, it is an object of the invention to provide a pen with illuminator having a single LED chip, which can nevertheless illuminate relatively uniformly the writing surface and can be manufactured relatively readily and inexpensively.
The object discussed above is solved according to the invention by a pen with illuminator comprising a writing element having a reservoir tube and a nib; a barrel for accommodating the writing element and having a front end opening; a light emitting diode unit having a carrier made of light transmittible material and a light emitting diode chip embedded in the carrier, the light emitting diode unit being mounted in the front end opening to expose at least a part of the carrier to the exterior and having a central penetrating hole for allowing the nib of the writing element to pass therethrough; a dry battery for providing the light emitting diode chip with electrical energy; a switching means for switching the electrical connection between the light emitting diode chip and the dry battery; and means for reflecting light emitted from the light emitting diode chip toward a predetermined direction. Since the light emitting of the LED chip can be transmitted to the opposite direction of the chip in the carrier by the reflecting means, it is possible to obtain relatively uniform illumination by using a single chip.
The reflecting means may be formed as a reflecting layer surrounding cylindrically the carrier of the light emitting diode unit, and the reflecting layer can be obtained by coating the inner wall surface of said front end opening with reflecting material. Otherwise, the reflecting means may be embeded in the carrier in a form of a reflecting plate. In the case, the reflecting plate can also serve as a connecting terminal for the light emitting diode chip.
It is, preferabe that the carrier of the LED unit contains light dispersing material to increase the dispersing of the light in the carrier to aid uniform illumination therein.